McGill research provides insight into the factors that may lead to vaccine hesitancy among older adults, who are known to be at increased risk of severe symptoms from COVID-19.

In the fall of 2020, before vaccines were readily available, the Canadian Longitudinal Study on Aging (CLSA) surveyed nearly 24,000 middle-aged and older adults to test their willingness to get vaccinated. The new study from McGill and McMaster and Universities, published recently in the American Journal of Epidemiology, provides insight into the factors that may lead to vaccine hesitancy among older adults, who are known to be at increased risk of severe symptoms from COVID-19.

Only a small percentage of people are hard to convince

The researchers found that roughly 84 % of adults surveyed over age 50 were very or somewhat likely to get a COVID-19 vaccine, approximately 10 % were uncertain, and only 6% per cent were very or somewhat unlikely to receive the vaccine.
The results of the survey are similar to current vaccination uptake rates in Canada, suggesting that both those who were uncertain and those who were very or somewhat likely to get vaccinated when surveyed, actually got vaccinated once they became eligible. Those who expressed uncertainty about it, did not.
“Even before COVID-19 vaccines became available in Canada, most older adults were willing to get vaccinated and they followed through once they could,” said Nicole Basta, the lead author on the study and an associate professor in the Department of Epidemiology and Biostatistics at McGill University. “Our study suggests that little headway has been made in convincing the small percentage of people who were initially unwilling to get vaccinated to actually get vaccinated in the year since vaccines became available.”

Safety concerns common among vaccine hesitant

The researchers determined that those who were unwilling to receive the vaccine were more likely to be younger (between 50 to 64 years old), female, have lower education and income, be non-white and live in a rural area. Concerns about safety and vaccine effectiveness were the most common reasons motivating those unlikely to receive the vaccine.
Previous vaccine history was another important factor associated with COVID-19 vaccine willingness. Individuals who had previously received a flu shot or had plans to receive a flu shot were also more willing to be vaccinated against COVID-19. In addition, willingness was also associated with believing one had never been infected with SARS-CoV-2, the virus that causes COVID-19, as was experiencing negative pandemic consequences.

Targeted outreach to improve vaccination rates

“Ensuring high COVID-19 vaccination rates – especially among older adults who are at increased risk for severe symptoms – is critical,” said Raina, a professor in the Department of Health Research Methodology, Evidence, and Impact at McMaster and the scientific director of the McMaster Institute for Research on Aging. “Our primary goal was to identify those who would benefit most from targeted outreach to improve COVID-19 vaccine uptake and provide much-needed evidence to inform vaccination programs.”


Source: McGill University
Full bibliographic information
Factors Associated with Willingness to Receive a COVID-19 Vaccine among 23,819 Adults Aged 50 years and Older: An Analysis of the Canadian Longitudinal Study on Aging” by Nicole E Basta, Nazmul Sohel, Giorgia Sulis, Christina Wolfson, Geva Maimon, Lauren E Griffith, Susan Kirkland, Jacqueline M McMillan, Mary Thompson and Parminder Raina was published in American Journal of Epidemiology.